|Number|Driver|Entrant|Chassis|Engine|Tyre|
|---|---|---|---|---|---|
|1|Jimmy Bryan|Dean Van Lines|Kuzma|Offenhauser|F|
|2|John Lawrence|Ecurie Ecosse|Jaguar D-Type|Jaguar|D|
|4|Jack Fairman|Ecurie Ecosse|Jaguar D-Type|Jaguar|D|
|6|Ninian Sanderson|Ecurie Ecosse|Jaguar D-Type|Jaguar|D|
|7|Bob Veith|Bob Estes|Phillips|Offenhauser|F|
|8|Jean Behra|Maserati|Maserati 250F|Maserati|F|
|8|Jean Behra|Maserati|Maserati 450S1|Maserati|F|
|12|Pat O'Connor|Sumar|Kurtis Kraft 500G|Offenhauser|F|
|16|Mario Bornigia|Scuderia Cottione|Ferrari|Ferrari|?|
|27|Tony Bettenhausen|Novi Auto Air Conditioning|Kurtis Kraft 500F|Novi (s/c)|F|
|35|Eddie Sachs|Jim Robbins|Kurtis Kraft 500G|Offenhauser|F|
|49|Ray Crawford|Meguiar Mirror Glaze|Kurtis Kraft 500G|Offenhauser|F|
|52|Troy Ruttman|John Zink|Watson|Offenhauser|F|
|52|Jim Rathmann2|John Zink|Watson|Offenhauser|F|
|54|Paul Russo|Novi Auto Air Conditioning|Kurtis Kraft 500F|Novi (s/c)|F|
|73|Andy Linden|McNamara Veedol|Kurtis Kraft 500G|Offenhauser|F|
|98|Johnnie Parsons|Agajanian|Kuzma|Offenhauser|F|

Question: what was the total number of us drivers?
Answer: 11